(a) Field of the Invention
This invention relates to a system for the simultaneous generation of mechanical motion and voltage. In one particular embodiment, it relates to portable audio cassette players.
(b) Description of the Prior Art
In many parts of the world there are locations without electric power lines. This means that electrical devices need to be battery operated. Moreover, in many such regions, batteries can be difficult to obtain and may furthermore be relatively expensive.
In many instances travellers, who rely on batteries to power electrical devices, may be disappointed when the batteries run out. In Arctic regions, it is known that batteries lose power rapidly dependent on the temperature. Loss of battery power for electrically-powered devices would be serious. In many other instances for emergency application, an electrical device may not be used frequently but it must be reliable when such use is essential. Under such conditions, batteries must be checked periodically to ensure that power is available as and when required.
Playback equipment for audio recordings is well known. Earliest examples of audio players were phonographs for reproducing sound recorded as an unevenness in the surfaces of grooves formed upon records. These initially were cylindrical and later were made in a flat circular form. In the use of a phonograph for playing flat records, for instance, a record is rotated upon a turntable beneath a tone arm which, in known manner, is caused to vibrate by its engagement with the uneven groove surface of the record. These vibrations are converted into electrical impulses corresponding to the vibrations and these impulses are transmitted to an amplifier which amplifies the impulses as sound. Originally, prime movers comprising manually windable driving springs were incorporated into phonographs for rotating turntables. Examples of such constructions are shown, for instance, in early Canadian Patent No. 222,126 granted in 1922, Canadian Patent No. 286,381 granted in 1929 and Canadian Patent No. 301,670 granted in 1930. In these patents, governors are described as being incorporated to ensure that the turntables are rotated at a controlled constant speed.
While mechanical prime movers were used for rotating turntables during early designs of phonographs and such prime movers were used over a lengthy period of years, the phonographs were, for all other purposes, operated by electrical power. As advancements were made in electrical engineering and new electrical devices were being developed and were being improved, after the 1920's, new designs of phonographs incorporated electrically powered driving means for rotating the turntables. As a result, from that particular time onwards all operations, including the driving of turntables, of phonographs have been operated by electrical power.
More recently, audio cassette and then compact disc technology has been developed as other means of recording sound. Audio cassette players and compact disc players are operated completely by electrical power, as is only to be expected with present technical knowledge. Electrical power for this purpose is provided either from the general electrical power supply, or, in the case of portable audio cassette and compact disc players, from batteries.
There are problems, however, with present-day batteries which may detract, under certain conditions, from the appeal of audio cassette players and compact disc players. For instance, in extremely cold weather conditions, batteries are known to lose power and this may result in a failure in their operation. In addition, present-day batteries have a limited useful life under any temperature condition and replacement batteries may be difficult or even impossible to find in certain geographical regions.
Recognition of many of the above problems was provided in G.B. Patent Application No. GB 2,262,324 A, published 16.06.1993 in the name of T. G. Baylis. That publication provided an electrical generator for powering a radio which comprised a spring motor which was wound up by way of a key such that the subsequent rotation of a torque drum as the stressed spring unwound therefrom generates electrical power. The rotational speed of the drum was geared up by gear means and rotated the rotor of an electrical motor to generate an output voltage. The output voltage was regulated by way of a Zener diode and was fed to a radio by way of a jack plug.